[Connexin 43 (Cx43) inhibits autophagy of rat thoracic aortic smooth muscle cells induced by ox-LDL].

Objective To investigate the role of connexin 43 (Cx43) in the autophagy of rat thoracic aortic vascular smooth muscle cells (VSMCs) induced by oxidized low-density lipoprotein (ox-LDL). Methods The primary VSMCs were identified by immunofluorescence cytochemical staining of α-smooth muscle actin (α-SMA). After ox-LDL treatment, the foam cells were identified by oil red O staining; the expression of microtubule associated protein 1 light chain 3 (LC3) protein in VSMCs treated with 0, 40, 80, 160 μg/mL ox-LDL for 0, 6, 12, 24 hours and the expression of Cx43 protein treated with 80 μg/mL ox-LDL for 24 hours were detected by Western blotting. VSMCs were randomly divided into control group, ox-LDL group, and ox-LDL combined with Cx43 specific antagonist Gap26 group to detect the expressions of LC3 and beclin 1 by Western blotting. Results The positive rate of α-SMA in the isolated cells was more than 95%. The oil red O positive cells in ox-LDL treated cells significantly increased, ox-LDL decreased the ratio of LC3II/LC3I and the expression of beclin 1 protein in a concentration- and time-dependent manner, and the expression of Cx43 protein was significantly increased. After administration of Gap26, the ratio of LC3II/LC3I and the expression of beclin 1 protein were up-regulated. Conclusion Cx43 inhibits autophagy of VSMCs induced by ox-LDL. Cx43 inhibits ox-LDL induced autophagy.